Jeff’s Note #
Unlike generic exam dumps, ADH analyzes this scenario through the lens of a Real-World Lead Developer.
For DVA-C02 candidates, the confusion often lies in choosing the right AWS service for automated deployments that support repeatability and rollback. In production, this is about knowing exactly which service handles both infrastructure setup and application lifecycle management with minimal manual intervention. Let’s drill down.
The Certification Drill (Simulated Question) #
Scenario #
StreamlineWorks, a fast-growing SaaS company, wants to automate deployment of their web app across multiple Amazon EC2 instances. They need a process that can repeat deployments consistently, install and update the application on each instance, create identical environments, and support rollbacks to previous versions when things go wrong. Their dev team wants to use a code-based template to automate these deployments, avoiding manual steps and ensuring consistency.
The Requirement: #
Identify the best AWS solution enabling infrastructure provisioning and automated deployment/updates on EC2 instances, with support for identical environment creation and rollback capabilities.
The Options #
- A) Use AWS Amplify for automatic deployment templates. Apply traffic-splitting deployment to replicate deployments. Modify any resources created by Amplify, if needed.
- B) Use AWS CodeBuild for automatic deployment. Upload an AppSpec file template. Store the appspec.yml in the root folder of the revision. Define a deployment group including the EC2 instances.
- C) Use AWS CloudFormation to create an infrastructure template in JSON format that deploys EC2 instances. Use CloudFormation helper scripts to install software and launch the app, calling scripts directly from the template.
- D) Use AWS AppSync to deploy the application. Upload the template as a GraphQL schema. Specify EC2 instances as deployment targets. Use resolvers for version control and updates.
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Correct Answer #
B.
Quick Insight: The Developer Imperative #
Use AWS CodeDeploy (triggered by AWS CodeBuild or CI/CD pipeline) with an AppSpec file for managing application lifecycle on EC2 instances. This supports repeatable deployments, updates, and rollback natively, unlike CloudFormation which focuses on infrastructure provisioning rather than app deployment orchestration.
Content Locked: The Expert Analysis #
You’ve identified the answer. But do you know the implementation details that separate a Junior from a Senior?
The Expert’s Analysis #
Correct Answer #
Option B
The Winning Logic #
AWS CodeDeploy is purpose-built for application deployment lifecycle management on EC2 instances. The use of an AppSpec file allows you to specify lifecycle hooks, file locations, and scripts to run during install and updates. You can define deployment groups targeting specific EC2 instances, enabling repeatable, consistent deployments. Most importantly, CodeDeploy natively supports rollbacks to prior versions if a deployment fails.
While CloudFormation (Option C) excels at infrastructure provisioning—including launching EC2 instances—it’s not designed to orchestrate application installs or rolling updates on instances after deployment without complex scripting. AppSpec and CodeDeploy handle this more cleanly.
Amplify (Option A) is oriented around frontend and mobile app deployment, not managing EC2 instance deployments. AppSync (Option D) is a GraphQL service, unrelated to EC2 app deployments.
The Trap (Distractor Analysis): #
- Why not A? Amplify doesn’t automate backend EC2 app deployments or support traffic-splitting for EC2 deployment groups—it’s frontend focused.
- Why not C? CloudFormation templates can provision infrastructure but managing application lifecycle requires additional scripting and manual processes; it lacks built-in rollback for app versions.
- Why not D? AppSync is for real-time GraphQL APIs, not deployment automation—this is a misuse of the service.
The Technical Blueprint #
# Sample AWS CLI snippet to create a deployment group with CodeDeploy
aws deploy create-deployment-group \
--application-name MyApp \
--deployment-group-name WebServerGroup \
--ec2-tag-filters Key=Environment,Value=Production,Type=KEY_AND_VALUE \
--service-role-arn arn:aws:iam::123456789012:role/CodeDeployServiceRole
The Comparative Analysis (Developer Perspective) #
| Option | API Complexity | Performance | Use Case |
|---|---|---|---|
| A | Low - Amplify API | Not suitable for EC2 | Frontend/mobile-focused deployment |
| B | Medium - CodeDeploy with AppSpec | High - automated lifecycle management | Best for EC2 app deployments with rollback |
| C | High - CloudFormation templates and custom scripts | Variable, manual app update management | Infrastructure provisioning (not recommended alone for app lifecycle) |
| D | High - AppSync APIs | Not applicable | GraphQL data service, not deployment |
Real-World Application (Practitioner Insight) #
Exam Rule #
For the exam, always pick CodeDeploy when you see automated EC2 application deployments with rollback and lifecycle hooks.
Real World #
In real scenarios, teams often combine CloudFormation for provisioning EC2 instances and CodeDeploy (or CodePipeline integrated with CodeBuild) to manage application deployment and updates—each tool serving its own specialized function but working in concert.
(CTA) Stop Guessing, Start Mastering #
Disclaimer
This is a study note based on simulated scenarios for the AWS DVA-C02 exam.